Exosomes from prostate cancer cell lines: Isolation optimisation and characterisation

Exosomes are considered to be a rich source of biomarkers, hence in this article we examine the best procedure for their isolation. We examine several isolation procedures, exosome storage conditions and other conditions affecting exosome production by prostate cell lines. We selected four different commercially available kits based on different principles to achieve exosome isolation, the best being magnetic-based. In addition, we found storage at - 20 degrees C to be good for storing isolated exosomes and that exosomes were produced from the cancerous prostate cell line 22Rv1 in much greater amounts than the non-cancerous prostate cell line RWPE1. We also found differences in the response of both cell lines in the production of exosomes as a result of stress, i.e. exposure to hydrogen peroxide and starvation. The effect of Triton X-100 on exosome lysis was examined using two different surfactant concentrations by analysis of the exosome count and change in the exosome size. The final part of the article details the advantages of the use of a 2D biochip prepared in-house over a commercially available 3D biochip for monitoring the interaction of exosomes via its surface receptors (CD63) with an immobilised ligand (anti-CD63 antibodies) using surface plasmon resonance. The final experiment shows the potential of lectin fluorescent microarrays for the analysis of glycans present in lysed exosomes.

Automated summary

This article examines the best procedure for isolating exosomes, which are considered to be a rich source of biomarkers. The study compared several isolation procedures and found that magnetic-based kits were the most effective. It also determined that storing isolated exosomes at -20°C is optimal and observed that cancerous prostate cell lines produce more exosomes than non-cancerous cell lines. Additionally, the study explored the response of cell lines to stress and investigated the effect of Triton X-100 on exosome lysis. The article concludes by discussing the advantages of using a self-made 2D biochip for monitoring exosome interactions and the potential of lectin fluorescent microarrays for analyzing glycans in lysed exosomes.